A league source said Delmas, who contributed 64 tackles, two sacks and three interceptions last season, signed a one-year deal that has a maximum value of $3.5 million if bonuses and incentives are achieved.

Delmas is allowed to sign a contract before Tuesday's 4 p.m. start to free agency because he was released by the Lions earlier this month.

Delmas started 64 games for the Lions, contributing 331 tackles, two forced fumbles, six interceptions and one safety in his five-year NFL seasons.

The 2009 second-round pick, who is a product of North Miami Beach High, was rated by ProFootballFocus.com as the 26th best safety in the NFL last season based on all the safeties who played at least 25 percent of their team's snaps.

He'll likely replace Chris Clemons, who spent the past season as the safety paired with Reshad Jones, and his signing likely means the Dolphins are no longer in the running to sign free agent safety Jairus Byrd.

Opposing quarterbacks had a 79.8 passer rating when throwing into Delmas' area last season, and completed 43.8 percent of passes when throwing to players Delmas was covering.

Delmas, who turns 27 in April, has consistently battled troublesome injuries throughout his NFL career, most of which stem from knee problems. He has missed 13 games in the 2011 and 2012 season, but played every game last season.

Because Delmas only signed a one-year deal it is possible the Dolphins will also address the position in 2014 draft, which is filled with a few promising free safeties.